Engine for air-pumps.



No. 630,380. Patented Aug. s, |899. w. B. MANN.

Erasme Fon Am Pumps.

(Application Sled Jan. 11, 1899.)

(No Model.)

m: wams paens co. Pnorou'rno.. wAsHmomN, o. c.

UNITED STATES 2 PATENT rricn.

WILLIAM MANN, or BALTIMORE, MARYLAND.

ENGIN FOR All-PUMPS'.

SPECIFICATION forming part of Letters Patent No. 630,380, dated August S, 1899. Appiicaion mea January 11,1899. serial No. 701,855. ci@ mais.)

To all whom t may concern.-

zen of the United States, and a resident of the city of Baltimore, State of Maryland, have invented a new and useful Improvement in Engines forAir-Pumps, Which invention is fully set forth in the following specification. v

Thisinvention relates to means for conipressing air or other gases, and has particular relation to a compressor designed for use in connection with air-brake systems for railways and similar purposes, and has for its objects to simplify the construction of such compressors, to increase their eiiiciency and facilitate the repair of the same, and to provide a compressor which shall be inexpensive to manufacture.

With these objects in view the invention consists of the usual air and steam cylinders, with their pistons connected by a suitable piston-rod, and a steam-chest on the steamcylinderl having therein a compound valve mechanism controlling the alternate admission of steam to andthe exhaust thereof from the two ends of the steam-cylinder, which valve mechanism is actuated by steam taken from the steam-cylinder into the steam-chest near the completion of each stroke of the piston, and means Without the steam-chest` and wholly independent of said valver mechanism for controlling the admission of steam from the steam-cylinder to the steam-chest. By thus providing valve controlling means wholly without the steam-chest 'and disconnected from the valvemechanism of the chest I insure the working of the latter with a minimum amount of friction, which contributes to the greater accuracy ofthe device as a whole. A

While various means may be employed to eect the control of the steam passing fromV the steam-cylinder to the steam-chest to operate the valve mechanism of the latter, I pre-i fer to employ piston-valves subjected to differential pressures, whereby they are operated at the proper moment to openor close by-passages from the steam-cylinder to the steam-chest, so as to eiect the shifting of the valve mechanism of the latter to permit the entranceof live steam into the steam-cylinder alternately on opposite sides of its piston to effect the reciprocation thereof. The cyl- In order to facilitate inspection and repairs,

the steam-chest and piston-valves controlling the lay-passages may be and preferably are all located within the head of the steam-cylinder, so that by removing the latter and substituting an interchangeable head a locomotive VInay be retained in active use While the removed cylinder-head, with its steam-chest and connected parts, is in the shop for repairs; but the invention is not limited to such location of the steam-chest, as it may be placed in any position on the cylinder which may be desired and still be within the scope of my invention.`

In the drawings forminga part of this speciication I have illustrated my invention, said drawings being designed, however, merely to facilitate the'proper understanding of the invention and not as defining the limits thereof.

In said drawings, Figure l is a vertical longitudinal section of the steam andair cylinders and steamchest, parts being kshown in elevation and with the several valves inthe positions they occupy at the instant the piston of the steam-cylinder has completed its upstroke. Fig. 2 is a like view of the steamcylinder with the valves in the positions they occupy at the instant the piston of the steamcylinder has completed its downstroke. Fig. 3 is a similar view of a modification, the positions of the parts corresponding to Fig. l; and Fig. 4 is a view of such modification with the parts in positions corresponding to Fig. 2.

Referring to Figs. 1 and 2, A indicates a steam-cylinder; B,acompressorcylinder; A', a piston in cylinder A; B', a piston in cylinder B, and C a rod. connecting. the two pistons, while c c indicate suitable rods or pillars holding the cylinders A and B in xed relation to each other. Y

D is a steam-chest, preferably arranged on the head of the cylinder A, as shown, and may, if desired, be made integral therewith. I prefer to form this chest D in the shape of IOO a uniform cylinder, closed'at each end by suitable heads D D2, which may be boltedor otherwise securely attached to the chest D. The chest has communication with a source Vby-.passagesffconnect the ends of the -steam- *chest with the cylinder A, one of them, as f," 2ov i pyortsd d' leading from one end portion thereof 'to the atmosphere and similar exhaust-` ."ports d2 d2 'leadingfrornthe other en'd .portion of live steam through a pipe E, which in the construction shown in Figs. 1 and 2 enters the cylinder through the branch passages e e', which enter the cylinder in proximity to but in opposite sides of its longitudinal center. i

Working passages a a connect the steamchest D to the cylinder A, one, as a, extending to one-end ofthe cylinder Aand the other, h a, to the opposite end thereof. It will beY noted that passages a a' connect with the steam-chest D on opposite sides of the longi-` tudinal center of said chest and in different transverse planes fromthe passages e e. Two

entering said cylinder at a point where the pi's'ton A just passes it upon the completion of its stroke'inone direction'a'nd the other, f',

entering at apoint where the piston justpasses l it upon the 'completion of its 'stroke in the opposite direction.

located piston-valves, as f4 f5, the by-Lpassages entering said cylinders at one end, where a Valveseat is formed,andleavingthecylind'ers atapointonthe side'the'reof removed from-said end, so that when 'the piston-valves f4 f5 are seatedthe by-'passages are closed and steam t communication from the cylinder'to the chest along the luy-passages is cut off. 'Cylinder-f2 'is connected toworking passage a by a branch passage a2, which enters cylinder f2 at 'the` lend thereof opposite the valve-seat, and pas- Astaged 4is connected lto cylinder f2 by a like ',passage, 'which enters the cylinder at the end thereof opposite the valve-'seat formed' therein. e v

The cylihdricalsteam-che'st AD has exhaustto the atmosphere, Vthe exhaust-ports dd 'be- 'ing'situatedin transverse planes between the "pointswhere the passages a and f 'enter the cylinder andthe ports 'cl2 d2 being situated in similar planes between the entrance-'points'of 'the passages a and f. The ports ald-2 are "the main exhaust-ports, 'through which the steam-cylinder 'is exhausted, and the ports rl d2 are the auxiliary exhaust-ports, through wh'ic'h lthe yends vof the steam-'chest are 'ex` "It will'be'readily understood that Within 'the cylindrical Steam-chest/13H1,thel

'form shown in Figs. l and 2 are fou'r pistonthe end D2 of the chest.

Each of saidby-passages ff traverses cylinders f2 f2, within which are y shown.

gether by a rod H. The piston 7L has a lug or projection t' extending from its outer face toward 'the end D of the steam-chest, and the piston h4 has a like lug fi extending toward These lugs i t" may be and preferably are mere extensions of the rod Hand are of suchl length as to impinge on the heads D D2 to determine the throw of the rod H and the valves carried thereby. The relative spacing of the pistons h', h2, h2, Vand 77,4 on the rod Il Aand of the several ports and passages leading into and out of the steam-chest is such that in the shifting of the rod and pistons, 'as will behereinafter described, the passages a d' ff' are alwaysopen or unobstructedthereby, while the passages e e and exhaust-ports d d d2 cl2 are alternately opened and closed.

The 'operation ofthe device as thus far described is as follows: Assuming the parts to be in the position shown in Fig. l, live steam is enteringthe'cylinder A by way of 'passages E e, steam-chest D, l(between piston-valves h 712,) and passage a and has driven the piston A Vpast the vinlet to the passage f', as The cylinder A'on thje upper side of the piston and the passage a'areexhausted through passage a' and'exhaust-portd2,wl1ile that portion of the steam-chest lyingbetween 'thepiston h and the Vhead D 'is open tojexhaust through port d'. The cylinders f2 f3 have a contracted opening on the `slide adjacent the passages f f', so thatwhe'nthe piston- `valves f4 f5 are'seated-as for example, f4 of Fig. l-there'is a lesssur'iace exposed to pressure by way'o'f by-passage f than "is exposed to "pressure 'by 'way of branch :passage ce2, the valve in thiszposiit'ion forming, in'eiect,fadifferential piston, and thereforethe live :steam v entering the cylinder f2, Fig. 1, through passage a2 'firmly holds 'the valve f? to 'its seat even after live stea'mjhas entered passage f. In f3, Fig. 1,'l1owever, the pressureto the rear of piston-valve fis about Athat ofthe atmosphere, and hence when piston A/in lassuming the position'of Fig. lpass'esthe yinouthor port `oi" passagef live 'steam from cylinder A enters passage f,"throws piston-valve f5 to'position shownin Fig. 1, and enters steam-chest D between piston h4 and'head D2. This will cause the'rod H and four piston-valves h" 71.2'h3`h4 to shift from position shown in Fig. 1 to Ithat shown in Fig. 2, thereby shutting o the owA of live steam to cylinder A'through passages e and t and'op'ening said cylinder to exhaust lthrough passage a and port d. ('Seie Fig. 2.) At the Sametime exhaust-ports d and d2 are c'losedby piston-valves h h4, respectively, and exhaust-port d2 is opened, whilejlivesteam enters cylinder 'A through passages e" and ct and acts on V.piston-valve f5by way'ofpassage ai., Vwhereby ythe valve is closed and the .piston A starts on its reverse `stroke--that is, 'from 'the position shown in lFig. v1 to that shown in Fig. 2. "During the time consumed by piston A in making its stroke pistonvalves h', h2, It-'and h4, rigidly connected to IOO IIO

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.pipe R'.

Valvesf1 andY f5 both remain seated; but when the piston A reaches the position shown in Fig. 2 live steam enters passage f, shifts "the piston-valvej'14 from the positionfshown in Fig. l to that shown in Fig. 2, and enter- Ving the steam-chest between piston h and head D shifts rod H and its four pistons from the position shown in Fig. 2 to that shown in Fig. 1. It will thus be seen that upon each stroke of the piston A' the pistonvalves in the steam-chest automatically shift so as to open the necessary steam and eX- haust ports to cause the reverse movement of the piston A. p

`Referring now to the compressing-cylinder 13,?) Z2 are ports communicating with the atmosphere and with passages b2 h3 within the Walls of the cylinder B. These passages b2 b3 communicate with the interior of the cylinder at the respective ends thereof. The ports b b are controlled by valves fu fu', opening inwardly, and immediately above said valves are other valves o2 o3, controlling communication between the passages b2 b3 and a third passage R, extending circumferentially around the cylinder B and preferably formed in the thickened walls thereof. The seats for the valves o o u2 U3 are preferably formed in bushings inserted in position through openings y y, closed by plugs y y', the relative positions of the plugs and valves being such that valves v o' may belifted from their seats by the incoming air, but cannot be displaced so as to fail to be properly reseated, because the valves o2 U3 prevent them from rising too far. Likewise the plugs y y' act as stops for valves u2 113. The bushings a: have ports or openings x2 therethrough, and it is by way of these openings that communication is had between the ports 1'; b and the passages b2 Z13. The circumferential passage Ris connected to a suitable reservoir by a (Shown in dotted lines in Fig. l.) The operation of the compressor is as follows: As the piston B makes its stroke from the position shown in Fig. l to the opposite end of the cylinder the air is forced through the passage b3, raises the valve r3, and enters the passage R, whence it is conveyed by pipe R to the reservoir. During the stroke of piston B there is a tendency to create a vacuum in the cylinder B above the piston, thereby permitting the atmospheric pressure on` valve i; through port b to lift said valve, whereupon air enters the cylinder B above piston B by way of port b and passage b2. The valve 122 remains seated during this operation, because the pressure above thevalvethat is, the pressure in passage R-exceeds atmospheric pressure, which tends to raise it. At the end of the stroke valves e o3 are returned to their seats by gravity, and upon the reverse stroke of piston B the compressed air in passages R and b2 firmly holds them seated, while valve o2 is lifted to permit the compressed air to flow from passage b3 to R, and valve o is opened by atmospheric presland the working passages a a leave the chest at points on opposite sides of the point where steam-pipe Eenters it-that is, intransverse planes lying on either side of said pipe. The piston-valves h' h4 control exhaust-ports d d cl2 cl3, as in the construction shown in Figs. 1 and 2; but valves h2 h3 are dispensed with, and instead a centrally-disposed valve hX, which during the reciprocations of the rod H plays back and forth across the mouth of pipe E', alternately cutting oif one of the working passages a a from communication with steampipe E and opening communication to the other. Piston-valves 7L h4 control the exhaust-ports exactly as in Figs. l and 2, and the operation of valves f4 f5 is also the same. I would remark that exhaust-ports d d' may, if desired, be formed as a single port, the piston-valve h' playing across it, so as to expose a portion of the port first on one side and then on the other, just as ports d d' are exposed in the construction shown, and the same is true of exhaust-ports d2 d3 and piston-valve h4, it only being essential that at each reciprocation of the exhaust piston-valve h or h4 it IOC) should close the chamber on one side of it to exhaust and openv the other, and vice versa.

It will be noted that the parts of my invention are of exceedingly simple construction, entirely free from spring action of any kind, strong, and not liable to get out of order. i It will also be noted that by reason of the fact that the steam-chest and by-passage valves are located on the cylinder-head they may be readily removed and taken to the shop for repairs, a second similar cylinder-head being substituted with very little diiiiculty or loss of time.

Having thus described my invention, what I claim is l. The combination of the steam-cylinder, and its piston with the steam-chest having communication with a source of live steam, working passages leading from the steamchest to opposite ends of the cylinder, by-passages leading from the steam-cylinder to opposite ends of the steam-chest, fluid-actuated valves controlling said by-passages, auxiliary exhaust-ports near the opposite ends of the steam-chest, piston-valves controlling said auxiliary exhaust-ports, main exhaust-ports and a valve device attached to and actuated by said piston-valves and controlling the passage of live steam through the steam-chest to said working passages, substantially as described.

2. The combination of the steam-cylinder and its piston, with the steam-chest having communication with a source of live steam,

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. wking :passages leading trom the steam-" 'tifngisteam vto lone of said working' passages and'tlien 'te the other, main andfaud'liaryex- 'iha'rst-'ports -rleai the Yopposite 'ends z'of Arthe` 'steam-@heist s piston Valves 'Cont-rolling, vsaid. pensata means .alternately admittingfsteam its pistn; *the Asteath-"elfe'slt contieeted 'to ja "cdnfneetirig lrefo'ther Working passage tlhereto, 'means "exhausting steam .from 'oppositel y'siflesfo'fsai'd piston exhaust-ports 'in Uh'estea'm' vchest, "piston-valves, playing :across said 'fexg steam @chest :behind itself; and

hau-st -aorts and connected `to 4'said steam-5 valve, bywpa'ssages -connecting the opzposiltet ends'ofthesteam-chest with fthe-steain-c'ylilwlg 'lifnrgsa'ic'l Ebypassages substantially 4as de-' fsciifbed.

'4. The eombinati'on 'of the i-Steamcyl-inder' and Lits piston with a Ystearmchest,fa Vsteamvalvealte'i-nately admitting steam tofapposite sides oflsaid pistoni, main' Jand auxiliary eX- 'ha-ustepdrts'in opposite ends of said steam-5 valve -an'd 1'centrol'liaflg said leX-htrust-L13'oits and 'means alternately admitting steam to y'said `lpistciin#valves fr'oi opposite en (is efth'e'steaiil- .-eyl'inder. y y

5. The s'(rmblrlation 'of tHe-steam-ylinei'; its piston', thefsteam-fehest 'and .steam-valve with a pai-ref pistons lopera'tively eo'nneete' to Said steamvalve, *ea'li pisto' 'don-trol liiig the 1ei-hamst Iof 'steam from fone `end off the' "steam-"cy-lindfera'nd -fl'om' the `s'pac'e Iill :tlie means alternatefiyadmfitting steam bem-nd :said pmol pistons; il y v6. 'Thecon-bi'nationfoffa `ste'am-'cy'linfllei, a

-cylindricalsteam=hest fhaving -a port fchttlte admission ief tive steam working ports fle-ad- "`i=ng"tefopposiite"ends oflthesteam-cylinderand `inai-n-afml auXfiliaye'xhau'stsports, Withaipislteh-Valve device reciprocating im tfhefylin- 'difie'alst'eamehestaudfcontrollingthelpassage 'f `steam throng-h .said v,Workiing "and lexhaust ports, and va'lvefGfn-trolled passages lea'difnfg from *near the feppesite ends df the steam- 'cylinder me Yopposite ends =of the steam-chest. der, amd "differential "pisto'nsvalves conft'rlg ing witnesses.

WILAM B. MANN.

`Witnessesz Y JOSEPH `T-. :GI-GTT, JAMES M. FArRBAN-K.

ssA 

